The present invention relates to a texturing unit of a false twisting texturing machine and particularly to calibrating the tensioning force meter for the thread.
The course of the thread in false twisting texturing machines differs with respect to the entrance and departure in the direction toward the front of or toward the rear of the texturing machine. In one case, the thread exits and is pulled off in the machine direction. In the other case, the exiting thread is pulled off in the direction away the machine. All of these texturing machines or units can be equipped with a thread tensioning force meter (see German patent P 35 06 698). Every thread tensioning force meter must be calibrated for the thread tensioning force over the spring element in the meter over which the thread travels. These thread tensioning force meters must be provided with corresponding thread guides at the inlet and the outlet of the meter for the thread guidance. The calibration is effected at a minimum load (for instance 20 cN) (Centi-Newtons) and with predetermined maximum load (for instance 80 cN).
If the thread is now withdrawn in the machine direction, the calibration point lies at the rear lowermost point of contact of the thread guide. Upon removal of the thread from the meter in the forward direction, this calibration point lies at the front edge of the thread guide.
Therefore two different calibrations processes are necessary. As a result, two different thread tensioning force meters are also necessary. These differently calibrated thread tensioning force meters cannot be distinguished from each other by their external appearance so that confusion between them can very easily occur, in addition to the requirement for double stocking of meters.
Since calibration of a force tensioning meter mounted in a specific machine can only be carried out with great difficulty, the calibration must be carried out on the thread tensioning force meter before it is installed in a machine. However, very frequently the manner or direction in which the thread is pulled off in the particular machine is unknown in advance of use. This has the result that thread tensioning force meters have to be recalibrated by the individual customer. The consequences of this are incorrect measurements and therefore defective yarns or high expenses for sending a mechanic for the disassembly, recalibration and reinstallation of the meter.